Dresden 2009 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 25: C/diamond II

HL 25.2: Vortrag

Dienstag, 24. März 2009, 16:15–16:30, POT 51

Theoretical studies of electronic transport and giant magnetoresistance in ferromagnetically contacted graphene nanoribbons — •Stefan Krompiewski — Institute of Molecular Physics, PAS, Poznan, Poland

Graphene − a monolayer of graphite − is believed to be even more promising for the emerging molecular electronics than carbon nanotubes. This contribution reports on a possible application potential of graphene nanoribbons also in magnetoelectronics (spintronics). The present methodology is based on the tight-binding model combined with the Green function recursive technique, within the ballistic transport regime. In contrast to hitherto existing theories, external magnetic contacts are here 3-dimensional and semi-infinite in the transport direction. The basic transport characteristics: conductance, shot noise and giant magnetoresistance (GMR) are studied for different aspect (width/length) ratios and the most common chiralities, i.e. zigzag and armchair ones. It turns out that typically the GMR effect at elevated gate voltages can exceed 10-20%, morover interestingly enough its value in armchair-edge ribbons is clearly higher than in those with zigzag edges.